When a body is thrown upwards, the maximum height it reaches depends on two
very obvious factors: 

1. the magnitude and direction of initial velocity 

2. the acceleration due to gravity on the planet 



Consider a body thrown vertically upwards, with an initial speed,
u. 

The motion can be described by the following equation (see Equations of Motion) 



If we consider the instant at which the object reaches its maximum height, v
= 0, so we have 



Looking at this equation, we see that, if objects are thrown upwards on
different planets but each time with the same initial speed,
we can say 



In other words the height the object will reach is inversely
proportional to the acceleration due to gravity at the place
considered. 

So, when comparing different planets, planet 1 and planet 2, we can write 



or 





see here for worked example 
